Digital data storage with increased robustness against data loss

摘要

Digital data is stored on a DASD by generating a parity block for a specified block of data items and storing the parity block at a selected location on the DASD. The parity block includes a parity computation calculated by applying a parity routine to the corresponding data. The parity block also includes a parity code that indicates either (1) the size of the corresponding data block, or (2) the number of data items contributing to the parity computation. The parity block may be stored adjacent to the corresponding data, or at an independent location. Among other things, the invention provides significantly increased robustness against data loss, and improved flexibility and efficiency in storing data.